Multi-functional worktable systems

ABSTRACT

A worktable has a supporting structure comprising folding elements (2, 3 and 4), and a top frame (1) along which worktop sections (5) may be selectively positioned to function as the jaws of a clamp or to function in conjunction with power tool support elements, here exampled as a sliding plate (6) for the attachment of a circular saw and a fence guide(7).

This invention relates to worktable systems of multi-functional use inconnection with building work, carpentry and the like.

Known, easily transportable systems for the clamping and handling ofworkpieces and/or the support or guidance of power tools are limited intheir capacity to deal with larger work material. They are also limitedin their versatility; clamping tables do not provide adequate saw tablefunctions, saw tables do not provide adequate clamping table functionsand neither provide drill table functions.

In general terms the present invention addresses itself to providing anintegrated system in which the worktable is a clamping table and/or asaw table and/or a drill table for example, in which the capacity tohandle larger material in all the mentioned functions is more thandouble that of known systems and in which for easy carrying andtransport the folding system is more compact than that of knownapparatus.

According to the present invention there is provided a worktable systemcomprising a supporting structure and two or more sections of planarworktop, two of which may serve as the jaws of a clamp, the saidsections being unattached, directly or indirectly to any fixed point onthe supporting structure such that in the terms of this invention theyare "freely displaceable" along the length of the supporting structureand may be locked in any selected position along that length. The meansof tightening forward one or both work top sections, in their functionas the jaws of a clamp, is carried together with the displacement of thesaid sections and takes place from the selected locked position.

In the terms of this invention the "supporting structure" would normallycomprise a top support with leg support structure but it could compriseof a top frame only.

Another aspect of the present invention provides a worktable systemcomprising a supporting structure and displaceable worktop sections inwhich one or more of the sections is provided with a channel or channelsand elements for clamping, machining or other purposes which may beinserted into the said channels.

From another aspect the invention provides a worktable system comprisinga supporting structure and displaceable worktop sections in which one ormore of the sections may have attached to it power tools, this toolplate section being selectively placed and locked into position toprovide with the other section or sections the most suitable support fora work piece, comprising also of elements associated with power tooloperations which may use the other section or sections as a fixing pointand/or guidance means.

From another aspect the invention provides a worktable system comprisinga supporting structure and displaceable worktop sections and means forpower tool guidance in the form of a straight edge which may be attachedto one of the worktop sections and pivoted to any selected angletraversing the work piece, comprising also of means for aligning andclamping the work piece.

From another aspect the invention provides an articulated tool supportand/or guidance system which attached to the supporting structure of theworktable may span the worktop sections or attached to a worktop sectionor sections may span a portion of their surface, the worktop sectionssupporting the work piece under the articulated tool support, comprisingalso of means for aligning and clamping the work piece.

From another aspect the invention provides a worktable system comprisinga supporting structure, a worktop secured to it and a plurality ofextension pieces releasably securable to said supporting structure, theproximal end being adjustably brought within the volume of theworktable, the distal end having a leg support, the said extensionpieces being joined by a cross-member which supports the work piece.

From another aspect the invention provides a worktable system comprisinga supporting structure and displaceable worktop sections in which theleg supports fold inward towards each other and in which the worktopsections may be removed from their operational position on thesupporting structure to be packed away within or attached to the foldedsupporting structure.

Embodiments of the invention will now be described, by way of exampleonly, with reference to the accompanying drawings, in which

FIG. 1 is a side view of a worktable with two jaw and one tool platesection;

FIG. 2 is a schematic side view of the worktable in FIG. 1 folded;

FIG. 3 is a side view of an alternative support structure in foldedposition with the jaws in operational position;

FIG. 4 is a schematic side view of the preferred embodiment for jawpositioner, jaw mount, jaw tightener and jaw;

FIG. 5 is a cross-section on the line 5--5 of FIG. 4;

FIG. 6 is a cross-section on the line 6--6 of FIG. 4;

FIG. 7 is a cross-section on the line 7--7 of FIG. 4;

FIG. 8 is a cross-section on the line 8--8 of FIG. 4;

FIG. 9 is a schematic plan view of FIG. 4 with the jaws removed;

FIG. 10 is a right end view of FIG. 4;

FIG. 11 is a partial schematic side view of an alternative jawpositioner which may be lifted off and press fitted down onto vertical,square comb section;

FIG. 12 is a schematic plan view of FIG. 11;

FIG. 13 is a cross-section view of a split jaw positioner at the pointwhere the two halves may be tightened onto the top frame;

FIG. 14 is a partial schematic side view of a jaw positioner which maypivot on the top frame;

FIG. 15 is a cross-section on the line 15--15 of FIG. 14;

FIG. 16 is a cross-section on the line 16--16 of FIG. 14;

FIG. 17 is an end view of a top section with channel inserts;

FIG. 18 is a schematic plan view of a clamp positioner element fittedinto a channel;

FIG. 19 is a plan view of FIG. 18 with axis rod and clamp piston added;

FIG. 20 is a plan view of FIG. 19 with cam-form clamp tightener;

FIG. 21 is a schematic plan view of FIG. 20 illustrating angledpositions for the clamp;

FIG. 22 is a cross-section on the line 22--22 of FIG. 20;

FIG. 23 is a plan view of a corner clamp element;

FIG. 24 is a schematic side view of a vertical clamp;

FIG. 25 is a partial end view of a sliding top;

FIG. 26 is a partial cross-section on the line 26--26 of FIG. 29;

FIG. 27 is an end view of a fence guide fitted to a channel;

FIG. 28 is a cross section of hole fitting for fence guide;

FIG. 29 is a plan view of the fence guide set for narrow cut;

FIG. 30 is a plan view of the max. width of rip-cut;

FIG. 31 is a plan view of a narrow cut on a panel;

FIG. 32 is a plan view of work table set for cross-cut;

FIG. 33 is a plan view of the angle plate;

FIG. 34 is a cross-section on the line 34--34 of FIG. 33;

FIG. 35 is a schematic plan view of the straight edge guide function;

FIG. 36 is an illustration of an element for attaching straight edgeguide;

FIG. 37 is a schematic side view of the straight edge guide and angleplate engaged with attachment element;

FIG. 38 is a schematic plan view of straight edge guide and angle platebefore engagement with the attachment element;

FIG. 39 is a schematic plan view of angle plate engaged with attachmentelement with straight edge guide pivoted to an angle;

FIG. 40 is a side view of an articulated tool support mounted to a topframe and spanning the jaws;

FIG. 41 is a schematic plan view of FIG. 40;

FIG. 42 is a schematic side view of interlocking cogged elements fittedto the secondary arms;

FIG. 43 is a schematic plan view at the point where the cogged elementsare joined by the link element and tertiary arms;

FIG. 44 is a side view of the link element with sliding guide;

FIG. 45 is a side view of an articulated tool support mounted to a worktop section;

FIG. 46 is a side view of an articulated tool support arranged for theguidance of a router plate;

FIG. 47 is a plan view of the link and router plate;

FIG. 48 is a schematic side view of the articulated tool support set forthe guidance of a circular saw;

FIG. 49 is a schematic side view of a sliding drill holder with attachedrecording wheel;

FIG. 50 is a plan view of extension pieces added to the top frame;

FIG. 51 is a schematic side view of the element which joins extensionrod, leg support and cross-member;

FIG. 52 is a schematic side view of the element in FIG. 51 but with theleg folded and the cross-member removed;

FIG. 53 is a schematic plan view of the swivel attachment of the legsupport to the extension rod;

FIG. 54 is a side view of a plug insert;

FIG. 55 is a schematic cross-section view of tubular top framecross-member with plug insert and nesting extension rod;

FIG. 56 is a side view of an attachment point for extension rods addedto the end of the table;

FIG. 57 is an end view of the extension rods with their leg supportswith panel loader attached to the cross-member;

FIG. 58 is a side view of the extension showing panel loader with panel.

Referring to FIG. 1, in the prefered forms of the invention a worktablecomprises a top frame 1 with inward folding leg supports 2 braced apartby removable struts 3 against blocking elements 4 and two or more freelydisplaceable work top sections 5 lockable in selected position along thetop frame as indicated by arrows A, two of which 5 may function as thejaws of a clamp or in other functions. As shown here they function witha freely displaceable tool plate section 6 the two sections beingselectively positioned in relation to the tool plate section to providethe most suitable support for a workpiece and/or as a fixing point foran element associated with a power tool operation, a fence guide 7 forexample.

One suitable form of construction for the worktable is that employed inladder fabrication: thus hollow section top frame and leg supportlengths joined by hollow section cross-members may provide lightness andrigidity.

In FIG. 2 the worktable structure of FIG. 1 is shown in folded position,the right hand leg support lying above the left hand leg support withinthe top frame, both leg supports having inserted dog-legged elements 8which off-centre them from the top frame cross-members which serve astheir axis points, this off-centring enabling them to nest one above theother while using axis points set at a common level.

The worktop sections are removable from their operational positionacross the length of the top frame and can be packed away in line withit either between the cross-members of the folded leg supports orattached to the outside of the folded structure.

In FIG. 3 another inward folding leg support system is shown in foldedposition the leg supports lying above each other under the top frame,having axis points 9 set at different levels within open rectanglesection leg brackets 10 attached to the top frame, the open inwardfacing side of the rectangle allowing the legs to fold inwards, theouter closed side being that which the leg supports are braced againstwhen folded out.

The two worktop sections are shown in operational position on the topframe because with the leg supports fully folded the worktable providesan even level stable base for low level clamping, of a door set on edgefor example.

Turning now to FIGS. 4 to 10 a detailed preferred embodiment for thedisplacement, locking and tightening forward of the work top sectionswill now be described. There are five principle elements: the worktopsection itself 5, the jaw mount 15 to which it is attached, the jawpositioner 11 which carries the jaw mount and locks into position on thetop frame, the suitable form of the top frame, in this example a channel13 and the jaw tightener 16 which may push the jaw mount forward.

Starting with the jaw positioner we see from FIGS. 5-8 that it straddlesthe top frame, the upper part of its body lying above but not on the topframe, with downward projections on each side of the top frame to theinside of which is fitted a male pivot-block element 12, a square withtwo of the opposite diagonal corners rounded, this element fittingprecisely into the top frame channel as shown in cross-section view FIG.8, the weight of the whole jaw system being carried by these malepivot-blocks.

The jaw positioner may be tilted slightly forward pivoting on theforward rounded corner of the male pivot-block and in this slightlyinclined plane it may be slid along the top frame channel, being lockedin position when returned to the horizontal plane by the squre cornersof the male pivot-block pressing against the upper and lower edges ofthe top frame channel, any further backward pressure on the jaws intheir clamping action only increasing the blocking force as it does withthe female pivot element on a conventional bar clamp.

A lock element 14 comprises a lever on the outside of the downwardprojections connected to a cam-form on the inside which when turnedpresses against the upper edge of the top frame channel to lock the jawpositioner in position when there is an absence of a clamping force toso do.

Turning now to the jaw mount we can see from FIGS. 4, 7 and 9 that itcomprises at its forward end of an upward cylindrical projection whichinserts into the jaw and permits partial rotation of the jaw around it,a flat body which may slide in the T-slot channel of the jaw positioner,the said body tapered inwards at its forward end to permit sidewaysmovement within the channel, broadening out at its rear end to preciselymatch the width of the T channel. A downward projection from the jawmount engages with a return spring 17 set in the body of the jawpositioner, the said spring keeping the jaw mount pushed against the jawtightener.

Sideways movement of the forward end of the jaw mount and turningmovement of the jaw around the jaw mount permit the jaws to function inan angled position but equally permits an easy sliding movement in whichone side of the worktop section may be moved forward or backward at adifferent rate to the other side thus avoiding any of the blockingmalfunction that can occur in simple sliding systems.

The jaw tightener comprises an eccentric circle or cam-form arrangementwith an axis point set in the body of the jaw positioner and a leverhandle extending outwards just under the jaw. When the lever is pulledbackwards the jaw mount is pushed forward, only limited movement forwardbeing required as the jaw may already be positioned in contact with theworkpiece.

A jaw mount block situated in the front end of the T-channel of the jawpositioner may be slid backwards to engage with the front end of the jawmount preventing lateral movement at this end.

FIGS. 11 to 16 show alternative embodiments for the jaw positioner. InFIGS. 11 and 12 for example there is shown a jaw positioner which may belifted vertically off a square comb section 19 which may run the lengthof the supporting structure and then may be repositioned, square combsection on the interior of the downward projections of the jawpositioner interlocking with the square section on the top frame.

In FIG. 13 there is shown a cross-section of a jaw positioner at a pointwhere a threaded element 20 may tighten together two split ends of thejaw positioner locking it onto the top frame.

In FIGS. 14 to 16 there is shown a jaw positioner wherein the body issupported by the top frame at a pivot point, tilting forward about thispoint disengages cogged section set on the inside of the downwardprojections from cogged track 21 on the top frame, the positioner beingdisplaceable along the top frame by sliding in an inclined plane andlockable in selected position when returned to the horizontal plane.

The invention also provides that the jaw positioner may enclose aroundor partially enclose around a supporting structure, for example in theform of a bar or tube using the female pivot blocking principle employedin conventional bar clamps.

The general provisions of the invention do not exclude other ways inwhich worktop sections usable as jaws may be given the means to befreely displaceable along the length of a supporting structure andlockable in selected position. While termed the jaw positioner thesystem may equally apply to worktop sections which do not have a jawfunctioning capacity.

The conventional worktop section usable as the jaws of a clamp employsholes in which inserts may be placed permitting jaw clamping on thesurface of the jaws as well as between the front edges. FIGS. 17 to 24show an alternative system of attachment and attachable elements.

In FIG. 17 there is shown a worktop section usable as a jaw withchannels in its upper surface. The channels may be formed in the mainbody material of the jaw and/or they may be additions to it as forexample in the embodiment shown in FIG. 22 where channel inserts inextruded aluminium are set into a dove-tailed channel in the wood of thejaw.

In FIGS. 18 to 20 there is shown a part by part build up of a clampingelement, first the clamp positioner 23 with a male pivot block portionin the channel and a portion above which disposes a hole for an axis,secondly the axis point 24 and a clamp piston 25 with slot permittingforward and backward movement and turning around said axis and finally acam-form element 26 with lever handle which may push the piston forward.The clamp may be positioned anywhere along the channel in contact withthe workpiece before being tightened to provide independent clamping onthe surface of the jaws which does not require tightening of the jaw.The line of clamping action may be in line with the length of the jaw asshown in FIG. 20 or set at an angle to it as shown in FIG. 21.

In FIG. 23 there is shown a clamping element 27 comprising a portionwhich slides in the channel and a portion which in "l" form lies above,the said clamp being selectively positioned along the jaw to follow andclamp the corner form of a workpiece, for example a mitred corner jointthe two parts of which may be held when the jaw is tightened.

In FIG. 24 there is shown a clamp element 29 comprising a portion whichslides in the channel and a portion which disposes a vertical clampingaction, the said element being selectively positioned anywhere along thelength of the jaws and lockable in position by means of a tighteningthread 30. The vertical clamp element may provide in addition toclamping the means of aligning a workpiece on the worktops.

The general provisions of the invention do not exclude other means ofproviding lengths along which a clamp element may be selectivelypositioned, for example a rail element added to conventional jaws whereholes normaly serve as the only insert points.

In FIG. 25 there is shown a freely displaceable worktop 31 whichsupported on both sides by the top frame may slide at a height belowthat of the jaw sections providing support for a workpiece being clampedbetween the jaws and/or as an additional work surface and/or as the lidfor a storage unit giving vertical access to that unit.

In the invention as so far described by the drawings the freelydisplaceable worktop sections have been presented primarily in their jawfunctioning aspect. FIGS. 26-34 describe them in another aspect in whichthey function with another worktop section.

In FIG. 26 there is a partial cross-section view along the line 26--26in FIG. 29 of a tool plate worktop section mounted at either side of theworktable on support elements 32 which may slide along the top frame,the said tool plate section being lockable in selected position by meansof a lever and threaded element 33 mounted in a further sliding element34 the said threaded element tightening the two sliding elementstogether onto the top frame. The tool plate section may equally bedisplaced and locked in position by a jaw positioner type element.

The tool plate work top section may have attached to its upper or undersurface by known conventional means power tools. In the embodimentsshown the example that is given is the attachment of a circular saw tothe underside of the tool plate and the related function of the otherworktop sections to this particular power tool but the generalprovisions of the invention do not exclude the mounting of other powertools nor the use of other elements associated with the particular powertool.

In FIG. 27 there is shown the mounting of a fence-guide to a channel ina worktop section, element 35 set in a channel on the underside of thefence guide 7 is slid into the worktop channel. FIG. 28 shows that anappropriately shaped element 36 may also attach a fence guide to aworktop with hole fitting points.

Tool plates which can be displaced by sliding are well known, normallycarrying a power tool on their upper surface, for example a circularsaw, along the length of the supporting structure across a workpiecepositioned below, machining that workpiece along a line parallel to thedisplacement of the said tool plate.

The system of tool plate displacement illustrated by way of example inFIGS. 29-31 is altogether different: the tool plate is displaced andlocked in a position selected to give the most appropriate support forand alignment with a workpiece which is then fed on to the power tool,being machined in a line perpendicular to the line of displacement ofthe tool plate.

In FIG. 29 the worktable is set up for a narrow width of rip-cut, thefence guide being fixed in the forward channel of a worktop section. InFIG. 30 the worktable is set up for the maximum width of rip-cut on astandard 1250 mm wide panel, indicated by dotted line A, the fence guidebeing fixed in the rear channel of a worktop section which is set to thefurthest end of the worktable, the tool plate section being set at thefurthest opposite end of the worktable. In FIG. 31 the worktable is setup for a smaller width of cut on the same panel, the tool plate beingpositioned to the right so that the portion of the panel left of the sawblade remains more securely supported by the worktable.

On a conventional worktable where the saw blade is situatedapproximately in the middle, other things being equal the max. width ofrip-cut is considerably below that of a displaceable system and equallythe support for the portion of panel left of the saw blade isconsiderably less. The advantage of narrow displaceable worktop sectionsis that they leave space for the displacement of the tool plate sectionwithout reducing support for the workpiece.

In FIGS. 32-34 there is shown a sliding table 37 which may feed aworkpiece, indicated by dotted line R, onto the sawblade for cross orangled cuts, the sliding table using the channels and/or the edges ofthe worktop section as guidance means. A plate 39 attached to thesliding table at a pivot point 40 is shown in FIG. 33 set up for across-cut of 90 degrees but may be turned clockwise, a curved slot 41running under a tightening element 42 which may lock the plate at aselected angle. A raised portion 43 may be fitted into the channel ofthe fence guide 7 which is mounted in the position indicated by dottedlines C in FIGS. 33 and 34. A support plate element 38 may be fitted tothe end of element 7 for the support of long workpieces. Runners 44attached to the underside of the sliding table may slide in the channelsof the worktop section.

FIGS. 35-39 illustrate another aspect of the invention in which theworktop sections may provide the fixing means for straight edge guidanceof a power tool across a workpiece and support, alignment and clampingof that workpiece.

In FIG. 35 there is shown a straight edge guide element 7 engaged with afixing point element 45 set on the end of a worktop section, the saidstraight edge traversing a workpiece as guidance for a circular saw 46.Fixing point element 45 is attached to the end of a worktop section, byinsertion into the channels for example, element 48 which disposes anaxis hole is inserted into the end of the straight edge guide and anangle plate 47 with axis projection is inserted into element 48. Thestraight edge guide with attached angle plate is slid across theworkpiece to engage with the fixing point. FIG. 38 shows the positionbefore engagement, FIG. 39 after engagement. Ribbed section on thefixing point may permit the angle plate to engage at a number ofvertically indexed points if fed in from a horizontal plane but preventsthe said angle plate from rising up vertically. A clamp sliding in achannel on the underside of the straight edge guide may clamp the saidguide to the worktop section at the other end, as indicated by position49 in FIG. 75 or to the workpiece if it overlaps the end of the worktopsection.

The vertical clamping element 29 may be positioned and fixed in thechannel of another worktop section to align a workpiece with the pointat which it is pushed up against the fixing point element. The straightedge guide may be angled s shown in FIG. 39.

FIGS. 40 and 49 illustrate another aspect of the invention wherein theworktop sections are used to support, clamp and align a workpiece underan articulated tool support and guidance system.

In FIGS. 40 and 41 there is shown an articulated tool support spanningthe worktops laterally and comprising two main arm frames 50 oneattached to each end of the supporting structure in pivotingrelationship, the main arm frames consisting of an arm on each side ofthe worktable joined by two round section cross-members. Attached to andarticulating around the top cross-member of each main arm frame is asecondary arm frame 51 also comprising an arm on each side of theworktable joined by two round section cross-members, the bottomcross-members of the secondary arm frames being joined at each end by atriangular link 52 with which they articulate. The triangular link isjoined at a lower mid-point by tertiary arms 53 to a critical point onthe main arms above or below which the articulation would block as itdescended but at which the triangular points at which the secondary andtertiary arms join the triangular link do not change in relation to eachother as the triangle rises or descends thus permitting straightlinedescent or rising of the system without blocking of the articulation.

The tops of the main arm frames are joined on each side of the worktableby rods which tighten the main arms towards each other the rods beingsynchronized in their movement by an axel with joined cogged wheels ateach end these wheels moving the cogged lengths on the tightening rods54. Tightening together of the main arms causes the secondaryarticulated structure to descend.

A holder for a power drill 55 may be fitted to the bottom cross-membersof the secondary arm frames and may be slid along it to selectedposition. This position may be determined with the aid of stop elements56 which may themselves be slid and locked into position.

FIG. 42 shows interlocking cogged elements 57 fitted into the bottomcross-members of the secondary arm frames the said elements keeping theangle between secondary arm frame and triangular link the same on eachside of the articulation. FIG. 43 shows a schematic plan view of thefitted cogged elements, triangular link and tertiary arms at the pointwhere they join the secondary arm frames. In FIG. 44 there is shownanother arrangement which may help the straight line vertical descentand rising of the system: two short arms 58 join the tertiary arms to aslide element 59 which runs in a channel on the triangular link element.

In FIG. 45 there is shown a simpler articulated structure without longcross-members, the said structure being mountable on a worktop sectionor sections spanning a large portion of their length. The articulatedstructure may hold a drill in a single position for vertical descentwithout the possibility of horizontal displacement. A workpiece may bealigned and clamped in selected position by vertical clamping elements29.

In FIGS. 46 and 47 there is shown an articulated tool support/guidancesystem arranged in an alternative way to guide a plate for holding arouter 60 along the bottom cross-members of the secondary arm frame, thecross-members being held further apart than in the drilling function bya wider link element 61.

In FIG. 48 there is shown a main arm frame linked to and articulatingwith a narrow straight edge guide 62 for circular saw or router, theother components being arranged by means of "S" hooks 63 to formextension support for a workpiece.

In FIG. 49 there is shown a recording wheel 64 attached to a drillholder the said wheel running in a track 65 along a lower cross-memberof a secondary arm frame, the wheel and the track may be cogged toprovide more accurate non-slip recording by the wheel. The recordingwheel, which can alternatively be attached to a power drill providingmeans for that attachment may measure distance between drilling pointsor if attached to a router the length of a routed channel or slot, themeasurement being displayed by the known means of a connected counter ordigital read-out.

In FIGS. 50 to 58 another aspect of the invention is illustrated, thatof extensions to the worktable supporting structure to permit the easyhandling of the large workpieces that may be machined on it.

In FIG. 50 there is shown a plan view of a top frame structure of aworktable to which tubular extension pieces 66 have been added, the saidpieces being adjustably nested within the volume of the worktable tosuitably position the distal work support end, the extension piecesadded to the width of the worktable being inserted into the tubularcross-members of the top frame and those added to the length beinginserted into elements 75 which are attached to a top frame cross-memberas shown in FIG. 56.

At the distal end of each extension piece there is a leg support 67comprising two leg members mounted on a double axis, the one whichpermits the leg members to fold outwards and be braced apart, the otherwhich permits them when folded together also to be folded up to theextension piece for compact carrying. The extension pieces are joined bytubular cross-members 68 around which the wheels adjustably positionedby sliding.

In FIGS. 51 to 53 the details of the elements joining an extensionpiece, leg support and cross member are shown. FIG. 53 is a plan view ofa double axis arrangement for joining a leg support to an extensionpiece: the leg members are joined by an axis 72 to an element 71 whichmay partially rotate around the extension piece to allow the leg membersto be braced apart. In FIG. 51 the leg support is shown in open positionthe tops of the leg members being indented into a recess of a two partclamp element 69 which may be tightened together by a lever 70 attachedto a threaded element joining the two parts. The clamp element alsoclamps the cross-member in place. In FIG. 52 the leg support is shownpivoted back around axis 72 revealing the recess in the clamp element.

In FIG. 54 there is shown a side view of a plug which may be partiallyinserted into the cross-members of the top frame and/or of the legsupports of the worktable, FIG. 55 showing a schematic cross-sectionview of an extension piece inserted, element 74 at the end of theextension piece having four lateral projections which may pass throughthe form of the plug insert, touching the inner wall of the cross-membersuch that the inserted extension piece is held without free-play.Extension pieces may be inserted into the bottom cross-members of theleg supports to give extendable feet which may add to the stability ofthe worktable.

In FIG. 57 there is shown an end view of two extension pieces with theirleg supports and a panel loader 78 which is attached to the extensioncross-member. In FIG. 58 there is shown a side view of a panel on theloader the loader being rotatable around its attachment points such thatthe panel may be pivoted to a horizontal plane on the extensions asindicated by dotted line A. Further supports 79 may be added to theextension system. A panel loader may also be attached to and rotateabout a cross-member of a top frame.

I claim:
 1. A worktable system comprising a supporting structure, atleast two worktop sections each of which is freely displaceable alongthe supporting structure, said worktop sections including first andsecond worktop sections having edges cooperating to form jaws of aworkpiece clamp, at least one of said first and second worktop sectionshaving mounted thereon for movement therewith clamping means operable toreleasably clamp said at least one of said first and second worktopsections to said supporting structure at a selected location, said atleast one of said first and second worktop sections further beingprovided with tightening means movable with said worktop section andoperable, when said worktop section is clamped in a desired location, totighten said worktop section forwardly towards another worktop section.2. A worktable section according to claim 1, in which said clampingmeans is unlocked by pivoting said at least one worktop section into aninclined position relative to said supporting structure, and is lockedby pivoting said at least one worktop section into alignment with saidsupporting structure.
 3. A worktable system according to claim 1, inwhich at least one of said first and second worktop sections is providedwith a guide channel which permits one or more functional elements to bemounted on and positionally adjusted on the respective worktop section.4. A worktable system according to claim 3, in which said functionalelement is a clamping member provided with tightening means for lockingthe clamping member in the guide channel.
 5. A worktable systemcomprising a supporting structure, and first and second worktop sectionsmounted on the supporting structure, said first and second worktopsections having edges cooperating to form jaws of a clamp, and at leastone of said first and second worktop sections being provided with aguide channel which permits one or more functional elements to bemounted on and positionally adjusted on the respective worktop section.6. A worktable system according to claim 1 or claim 5, including a thirdworktop section displaceable along said supporting structure at a levelbelow said first and second worktop sections.
 7. A worktable systemaccording to claim 1 or claim 5, in which said first worktop section isprovided with means for mounting a power tool.
 8. A worktable systemaccording to claim 7, in which said power tool mounting means comprisesmeans for guiding a power tool for movement relative to said firstworktop section.
 9. A worktable system according to claim 7, in whichsaid power tool mounting means comprises means for securing a power toolin a fixed position on said first worktop section is provided with guidemeans for guiding movement of a workpiece to the power tool, said guidemeans being selectively positionable on said second worktop section. 10.A worktable system according to claim 9, in which said guide means isarranged to feed said workpiece to said power tool in a first direction,and said first worktop section carrying said power tool is moveable onsaid supporting structure in a second direction perpendicular to saidfirst direction.
 11. A worktable system according to claim 8, in whichsaid power tool guiding means comprises a fixing means releasablyattachable to said first worktop section and a straight edge guideremovably received in said fixing means, and in which said secondworktop section has releasably attached thereto a clamping element forclamping and aligning said workpiece.
 12. A worktable system accordingto claim 1 or claim 5, including a power tool support removably mountedon said first worktop section, said power tool support comprising anarticulated mechanism spanning said first worktop section and movabletogether with the power tool toward and away from said first worktopsection.
 13. A worktable system according to claim 12, in which thepower tool is mounted for sliding movement along said power toolsupport.
 14. A worktable system according to claim 13, including adistance measuring device arranged to measure the distance travelled bythe power tool along said power tool support.
 15. A worktable systemcomprising a supporting structure and at least two worktop sectionsadjustably mounted on the supporting structure; and in which thesupporting structure comprises a generally box-shaped upper portion andfirst and second leg assemblies pivotally connected to said upperportion adjacent opposite ends thereof, at least one of said legassemblies being offset from its pivot axis such that said legassemblies may be moved between an open position in which said legassemblies support said upper portion at an operational height and aclosed position in which said leg assemblies are nested within saidupper portion and lie one above the other.
 16. A worktable systemaccording to claim 15, in which said upper portion comprises a top frameincluding at least one cross-member to which one of said leg assembliesis rotationally mounted.
 17. A worktable system according to claim 16,including a strut element extending between said leg assemblies in saidopen position.
 18. A worktable system according to claim 15, in whichsaid worktop sections are removable from said supporting structure andare dimensioned to be receivable within said upper portion when in saidclosed position.
 19. A worktable system according to claim 15, furthercomprising a worktop extension piece nested within said upper portionand adjustably extendable therefrom.
 20. A worktable system according toclaim 19, in which said extension piece is provided with support legs atan outer end thereof, said support legs comprising a pair of legspivoted to a member which in turn is pivotally mounted on the extensionpiece.
 21. A worktable system comprising a supporting structure, atleast two worktop sections adjustably mounted on the supportingstructure, and a panel loading device which comprises a planar supporthaving one end secured relative to said supporting structure for pivotalmovement about a horizontal axis and an outer end provided withpanel-locating stop means.
 22. A worktable system according to claim 21,in which a worktop extension piece is selectively mounted on saidsupporting structure, and said panel loading device is selectivelysecurable to said supporting structure and to said worktop extensionpiece.